简介:AbstractImportance:Tics usually start around 4-6 years old and affect about 1% of school-age children. Premonitory urges (PUs) are sensory phenomena that precede tics and are often described as unpleasant feelings. Recent evidence supports a relationship between PUs and tic severity, but reports are conflicting. In addition, there is no report of PUs in the Chinese population.Objective:To investigate the correlation between PUs and tic symptoms in the Chinese population with tic disorders.Methods:We recruited 252 Chinese individuals with chronic tic disorders (age 5-16 years). The Yale Global Tic Severity Scale (YGTSS) was used to assess tic symptoms, and the Premonitory Urge for Tics Scale (PUTS) was used to assess PUs. We calculated Spearman correlations between PUTS and YGTSS scores, and constructed a linear regression model to predict the tic symptom severity by PUs.Results:There was a significant positive correlation between PU severity (PUTS scores) and motor tic severity, total tic severity, tic-caused impairment (YGTSS scores) (P < 0.05). PU severity was a significant positive predictor of tic symptom severity (standardized beta coefficient = 0.174, t = 2.786, P = 0.006).Interpretation:We provide evidence for a correlation between PUs and tic symptoms. PU severity predicts tic symptom severity. Further research on PUs is needed to clarify the shared brain mechanism with tics, and their role in tic expression. A suitable tool to assess PUs in younger children is also needed.
简介:AnewapproachtothemassiveproductionofTiCwhiskerswithhighpurityandlowcostwaspresented.Itisamodifiedcarbothermalreductionmethod(MCTR)characterizedbyargonstreamflowingverticallyandpassingthroughtheinteriorofthemixtureofrawmaterials.Itisfoundforthefirsttimethatthereisanoptimumflowoftheupwardflowingargonstream,atwhichlargequantityofhighqualityTiCcanbeobtained.Thispaperdescribedthenewmethod,analyzedthemechanismandconditionsfortheformationofhighpurityTiCwhiskersonalargescale,andcomparedMCTRwiththetraditionalcarbothermalreductionmethod(TCTR).Basedontheanalysisandcomparison,itisconcludedthatinordertoproducehighqualitytransitionmetalcarbides,nitridesandcarbonitrideswithlowcostTCTRmustbereplacedbyMCTR.
简介:AbstractTic disorders (TD) is a neurodevelopmental disorder that is often first recognized in children and adolescents and is characterized mainly by motor and phonic tics. Drug treatment of TD has been criticized because of serious side effects, and TD treatment emphasizes behavioral psychotherapy. This study reviewed the most common behavioral psychotherapy for TD: habit reversal training (HRT). We examined the contents, variation, curative effects, and premonitory urge control of HRT and other behavioral psychotherapies. The findings suggest that current understanding of HRT is insufficient and further studies are needed. First, studies of online guidance training are needed to implement technology that can help more patients. Second, the future integration of HRT and other technologies is important. Third, imaging techniques could be used to further explore the brain mechanisms underlying HRT. Research on HRT for TD in China is insufficient. We call on more Chinese researchers to study, investigate, and develop technology to promote the development of behavioral psychotherapy for TD in China.
简介:Si3N4/TiCnanocompositeceramicshavebeenfabricatedbyhotpressingtechniquewithAl2O3andY2O3asadditives.TheresultsshowedthatwelldispersedcompositepowderwascarriedoutbyaddingdispersantandadjustingpHvaluesofsuspensions.RemarkableincreaseinflexuralstrengthatroomtemperatureswasobtainedbyaddingnanoparticlesinSi3N4matrixwith10%(wtpct)ofnano-Si3N4and15%ofnano-TiC.Theflexuralstrength,fracturetoughnessandhardnesswere1025MPa,7.5MPa·1/2and15.6GPa,respectively.Themicrostructuresofmaterialswereanalyzedbyscanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM),whichindicatedthatTiCnanoparticlesdistributeinthematrixandatthegrainboundaries.Accordingtothefractureform,lowcontentsofnanoparticlescouldrefinematrixgrainsandleadtothecrackdeflectionaswellascrackpinning.Themultiplexmicrostructurewasformedbymixingnano-Si3N4particles.Thecracktrajectoriesexhibitedcrackdeflection,rod-likegrainbridgingandpull-out.
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简介:通过微波烧结制备TiC/6061铝基复合材料,采用TEM、EDS、XRD分析该复合材料结合界面的结构、元素分布和相组成;从热力学角度研究新相的形成机理。结果表明:结合界面存在厚度约为100nm的扩散型和反应型2种中间层,其与基体和增强相的邻接整洁、边界连续、结合紧密。扩散型界面,具有(111)Al//(240)TiC,[011]Al//[001]TiC的晶体学位向关系并形成半共格界面;反应型界面,由TiAl和微纳米级的Al4W相组成。界面TiAl相的热力学形成机理为Al和Ti元素通过扩散的方式首先生成TiAl3,之后随Ti元素的进一步扩散占据TiAl3中Al的位置,最终形成TiAl。
简介:Inordertodevelopanew-typeTiC-TiNcontainingcarboncompositerefractorysoastoimprovetheservicelifeofblastfurnacehearth,thewettabilitybetweenthecarbonrefractoryandmoltenslagormetalhasbeenmea-sured.Itwasindicatedthatthecarbonrefractoryiswet-tedbyslag(θ≤90°)when(TiC+TiN)>33.52%,TheeffectsofTiNorTiConwettingbehaviorarebasi-callyidentical.WhentheamountofTiCinthecarboncom-positerefractoryisgreaterthan60%itwillbewettedbyhotmetal;therefore,thecarboncompositerefractorywillbewettedbyslagbutnotpermeatedbyhotmetalwhentheamountofTiCisrestricted.
简介:Anewhardfacingprocess,reactivebrazecoatingprocess(RBCC)wasstudied,and(TiC+Cr3C2)/FecompositecoatingswerepreparedbyRBCCusingcarbon,Cr3C2,iron,ferrochromiumandtitaniumpowderastherawmaterialsinvacuumbrazefurnace.TheresultsshowthatTiCisin-situsynthesizedinthecoatings.ThemethodsofintroducingCr3C2havegreateffectsonthedistributionofTiC.AddingCr3C2directlytotherawmaterialsforcoatings,fineTiCparticlesaggregateintodiscoidsparalleltothecoatingsurface,whereas,in-situsynthesizingCr3C2incoatings,theaggregationsofTiCarelumpish.Duringbrazecoating,Cr3C2particlesdirectlyaddeddissolveandprecipitatetobecomeneedle-shaped.Thecoatingshaveanevenandsmoothsurfaceandarecombinedwiththeirmildsteelsubstratesbyametallurgicalbonding.
简介:TiC/Cr18Ni8steelbondedcarbidesweresynthesizedbyvacuumsinteringwithmixedpowdersofiron,ferrotitanium,ferrochromium,colloidalgraphiteandnickelasrawmaterials.Themicrostructureandmicrohardnessofthesteelbondedcarbideswereanalyzedbyscanningelectronmicroscope(SEM),X-raydiffraction(XRD)andRockwellhardometer.ResultsshowthatthephasesofsteelbondedcarbidesmainlyconsistofTiCandFe-Cr-Nisolidsolution.ThesynthesizedTiCparticlesarefine.Mostofthemarenotmorethan1μm.Withtheincreaseofsinteringtemperature,theporosityofTiC/Cr18Ni8steelbondedcarbidesdecreasesandthedensityandhardnessincrease,butthesizeofTiCparticlesslightlyincreases.Underthesamesinteringconditions,thedensityandhardnessofsteelbondedcarbideswithC/Tiatomicratio0.9arehigherthanthosewithC/Tiatomicratio1.0.TheTiCparticleswithC/Tiatomicratio0.9aremuchfinerandmorehomogeneous.
简介:HotcompressionbehaviorofTiC–Al2O3/AlcompositeswasstudiedusingtheGleeble-1500systematatemperaturerangeof300–550°Candatstrainraterangeof0.01–10.00s-1.TheassociatedstructuralchangeswerestudiedbyTEMobservations.Theresultsshowthatstressleveldecreaseswithdeformationtemperatureincreasingandstrainratedecreasing,whichcanberepresentedbyaZener–Hollomonparameterinanexponent-typeequationwithhotdeformationactivationenergyQof172.56kJ·mol-1.Dynamicrecoveryoccurseasilywhenstrainratesarelessthan10.00s-1.Dynamicrecrystallizationcanoccuratstrainrateof10.00s-1.
简介:AbstractBackground:Tourette syndrome (TS) is a neuropsychiatric disorder with onset in childhood that warrants effective therapies. Gut microbiota can affect central physiology and function via the microbiota-gut-brain axis. Therefore, the gut microbiota plays an important role in some mental illnesses. A small clinical trial showed that fecal microbiota transplantation (FMT) may alleviate TS symptoms in children. Herein, FMT effects and mechanisms were explored in a TS mouse model.Methods:TS mice model (TSMO) (n = 80) were established with 3,3'-iminodipropionitrile, and 80 mice were used as controls. Mice were grouped into eight groups and were subjected to FMT with feces from children or mice with or without TS, or were given probiotics. Fecal specimens were collected 3 weeks after FMT. 16S rRNA sequencing, behavioral observation, and serum serotonin (5-HT) assay were performed. Differences between groups were analyzed using Mann-Whitney U test and Kolmogorov-Smirnov (KS) tests.Results:A total of 18 discriminative microbial signatures (linear discriminant analysis score > 3) that varied significantly between TS and healthy mice (CONH) were identified. A significant increase in Turicibacteraceae and Ruminococcaceae in TSMO after FMT was observed (P < 0.05). Compared with non-transplanted TSMO, the symptoms of those transplanted with feces from CONH were alleviated (W = 336, P = 0.046). In the probiotic and FMT experiments, the serum 5-HT levels significantly increased in TSMO that received probiotics (KS = 1.423, P = 0.035) and in those transplanted with feces from CONH (W= 336.5, P = 0.046) compared with TSMO without transplantation.Conclusions:This study suggests that FMT may ameliorate TS by promoting 5-HT secretion, and it provides new insights into the underlying mechanisms of FMT as a treatment for TS.